Centrifugal fan

ABSTRACT

A centrifugal fan assembly including a removable orifice ring having tabs thereon, the ring being formed from the material removed in the production of the side plate of the fan housing, the diameter of the orifice ring being substantially equal to the diameter of the opening in the side plate of the fan housing, the tabs on the orifice ring being utilized to locate the orifice ring on the side plate of the fan housing.

United States Patent 1 1 l 1111 3,803,690

Cann et al. Apr. 16,1974

[54] CENTRIFUGAL FAN 1,039,722 10/1912 Fullman .Q 29 416 3,145,910 8 1964 J 11 417/363 [75] Inventors: Peter Ca'm; 3,401,870 9i1968 C i'oi ve 417/363 1 both of Syracuse, NY.

[73] Assignee: Carrier Corporation, Syracuse, NY. Primary Examiner charles Lanham [22] Filed; June 2 972 Assistant ExaminerD'. C. Crane Attorney, Agent, or Firm-D. Peter Hochberg [21] Appl. No.: 265,069

Related US. Application Data [62] Division Of Set. N0. 129,717, March 31, 1971, Pat. [57] ABSTRACT A centrifugal fan assembly including a removable orifice ring having tabs thereon, the ring being formed g gisb from the material removed in the production of the 58] i 29/p156 8 6 415 side plate of the fan housing, the diameter of the orifice ring being substantially equal to the diameter of 29/411 1564 415/201 417/363 the opening in the side plate of the fan housing, the

tabs on the orifice ring being utilized to locate the ori- [56] References Cited fice ring on the side plate of the fan housing.

UNITED STATES PATENTS 2,948,055 8/1960 Baxteret al. 29 416 2 Claims, 5 Drawing Figures CENTRIFUGAL FAN This is a division, of application Ser. No. 129,717 filed Mar. 31, 1971, now Pat. No. 3,698,833.

BACKGROUND OF THE INVENTION Centrifugal fans generally comprise a fan wheel mounted for rotation within a scroll-shaped housing. The housing is provided with circular inlet openings centered with respect to the fan wheel shaft. To improve fan performance, the inlet openings are smaller than the outside diameter of the fan wheel. To assemble the fan, a portion of one side of the fan housing may be removably secured to the housing by bolts or sheet metal screws. Ordinarily, the side of the fan housing is provided with a circular opening slightly larger than the diameter of the fan wheel. An inlet or orifice ring having an outside diameter greater than the diameter of the opening in the housing and an inside diameter equal to the desired inlet opening diameter is placed over the opening in the fan housing and fasteners are inserted through the portion of the orifice ring and the portion of the housing which are in overlapping relationship to attach the orifice ring to the housing. A plurality of fas-.

teners are employed for this purpose. Since the outside diameter of the orifice ring is greater than the diameter of the opening in the side of the fan housing, the orifice ring and the side of the housing must be stamped from separate pieces of sheet metal stock.

SUMMARY OF THE INVENTION This invention relates to a centrifugal fan assembly and a method for manufacturing a fan housing having a scroll-shaped wrapper with first and second side plates secured thereto, the second side plate having a circular opening therein and a plurality of notches communicating with the circular opening. An orifice platehaving a central circular opening is provided, the plate being formed by the material removed from the second side plate to provide the circular opening therein, the orifice plate thereby having a diameter substantially equal to the diameter of the circular opening in the second side plate. The orifice plate has tabs formed thereon as a result of the formation of the notches in the second side plate. The tabs are adapted for engagement with the second side plate at a location circumferentially spaced from the notches in the second side plate to position the orifice plate on the second side plate over the circular opening therein.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a fan housing with the orifice plate removed therefrom;

FIG. 2 is an illustration of an orifice the fan housing of FIG. l;

FIG. 3 is a side view of a fan housing with the orifice plate of FIG. 2 placed thereon;

FIG. 4 is a side view of a centrifugal fan assembly with a portion broken away; and v FIG. 5 is a sectional view taken along line V-V- of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly to the drawing, there is illustrated a fan housing 3 comprised of a scroll-shaped wrapper 5, a first side plate 7 and a second side plate 9. Sideplate 7 is provided with an air inlet opening 8 plate for use with having a diameter less than the diameter of the fan wheel to be employed in the housing.

Side plate 9 and a circular orifice plate 11 are provided by blanking orifice plate 11 from side plate 9. Tabs 13 are formed on orifice plate 11 which results in notches 15 being formed in side plate 9. The diameter of opening '17 formed in side plate 9 by the removal of the orifice plate 11 therefrom is therefore substantially equal to the diameter of the orifice plate. An air inlet opening 18 in orifice plate 11 and the air inlet opening 8 in side plate 7 are provided for passage of air into the fan housing. I

A plurality of depressions 19, corresponding to the number of tabs formed on orifice plate 11, are formed in side plate 9. The depressions 19 are circumferentially spaced from notches 15 to receive tabs 13 and position orifice plate 11 in the plane of side plate 9. Depressions 19 preferably have a .depth substantially equal to the thickness of the second side plate, so that when tabs 13 are received therein orifice plate 11 is po- The circular opening 17 formed in side plate 9 is sized to allow insertion of a fan wheel 23 into the completed housing.

The notches 15 provide openings for insertion of resilient grommets 25 and bolts 27 to mount a fan motor support bracket 29 on the housing and secure the orifice plate within opening 17. The motor support bracket, which is adapted to support and position a fan motor 31 and the fan wheel 23 which is secured to the shaft of the fan motor, is provided with a plurality of arms 37 corresponding to the number of notches in side plate 9.

To mount the motor support bracket and the orifice plate on the fan housing, the resilient grommets, which have an enlarged headed portion.33, a central bore 35 and internally threaded insert 37, are inserted into the notches in the side plate after the orifice plate is positioned thereon with the tabs aligned with depressions 19. The bolts 27 are then inserted through openings in the motor support bracket arms, threaded into the grommets 25 and tightened. This causes the grommets to swell on the inner side of side plate 9 to resiliently secure orifice plate 11 and motor support bracket 29 on side plate 9. 1

It can be seen from the foregoing that a centrifugal fan assembly is provided which generates a minimum quantity of scrap material in the fabrication thereof and which requires a minimal number of fasteners forassembly. Further, the second side plate including the is not limited thereto, since it may be embodied within the scope of the following claims.

We claim:

1. A method for manufacturing a fan housing comprising the steps of:

forming first and second side plates,

stamping a circular disc with a central circular opening therein and radially extending tabs thereon from the second side plate to provide a circular I opening and radially extending notches in the secnd side plate for insertion of a fan wheel through the circular opening in the second side plate into the completed fan housing,

assembling the first and second side plates on a scroll member,

positioning the circular disc on the second side plate with the tabs on the circular disc circumferentially spaced from the notches on the second sideplate; and

inserting fasteners in the notches formed in the second side plate to fasten the circular disc on the second side plate.

2. A method for manufacturing a fan housing according to claim 1 further including the step of forming depressions in the second side plate adjacent the circular opening in the side plate and circumferentially spaced from the notches therein, the depressions having a depth substantially equal to the thickness of the second side plate, the circular disc being positioned on the second side plate with the tabs thereon disposed in the depressions formed in the second side plate so that the circular disc is positioned in the plane of the second side plate. 

1. A method for manufacturing a fan housing comprising the steps of: forming first and second side plates, stamping a circular disc with a central circular opening therein and radially extending tabs thereon from the second side plate to provide a circular opening and radially extending notches in the second side plate for insertion of a fan wheel through the circular opening in the second side plate into the completed fan housing, assembling the first and second side plates on a scroll member, positioning the cirCular disc on the second side plate with the tabs on the circular disc circumferentially spaced from the notches on the second side plate; and inserting fasteners in the notches formed in the second side plate to fasten the circular disc on the second side plate.
 2. A method for manufacturing a fan housing according to claim 1 further including the step of forming depressions in the second side plate adjacent the circular opening in the side plate and circumferentially spaced from the notches therein, the depressions having a depth substantially equal to the thickness of the second side plate, the circular disc being positioned on the second side plate with the tabs thereon disposed in the depressions formed in the second side plate so that the circular disc is positioned in the plane of the second side plate. 